1. Technical Field
The present invention is directed toward a process for reclaiming plastic containers. More particularly, the invention is useful when reclaiming plastic such as what is commonly known in the industry as one half liter, one liter, two liter and three liter polyethylene terephthalate containers or containers of similar composition. These types of containers are used in the beverage industry and are what are generally known as "disposable" containers. Various techniques have been developed for reclaiming and/or recycling plastic beverage containers. However, these various techniques have certain drawbacks which are not associated with the present invention.
U.S. Pat. No. 4,033,804 (Baldyga) discloses a process of reclaiming thermoplastic articles. Baldyga teaches that the bottle is delabeled by relieving orientation stresses beneath the label sufficiently to cause enough shrinkage for the bottle and the label to separate.
U.S. Pat. No. 3,317,642 (Bailey) teaches and describes a method for stabilizing the volume of a plastic container, such as a plastic milk bottle. In other words, Bailey discloses a method of producing plastic containers with calibrated volumes.
U.S. Pat. No. 3,662,453 (Meal, et al) discloses an apparatus and a process for stripping a heat shrinkable material extending peripherally about a rigid article such as an electrical connector.
U.S. Pat. No. 3,870,181 (Sincock) teaches the manufacture of a beverage bottle formed under pressure wherein the bottle consists primarily of polymerized acrylonitrile monomer.
U.S. Pat. No. 4,067,826 (Emery) teaches a method for recovering mixed plastic materials from the group consisting of at least polyvinyl chloride and polyethylene.
U.S. Pat. No. 4,599,131 (Matuszak) discloses a high speed rolling apparatus for delabeling plastic containers. Matuszak teaches that a series of rollers flatten the plastic bottle, that some of the rollers provide heat to the flattened bottle for loosening the bottle label, and that brush rollers eventually remove the label from the bottle.
Unfortunately, these prior approaches have their own set of drawbacks. For example, Baldyga (U.S. Pat. No. 4,033,804) requires shrinkage of the bottle before the label can be removed. Matuszak (U.S. Pat. No. 4,599,131) requires heat; that the bottle be flattened and thereafter scrubbed by brush rollers before the label can be removed.
The present invention does not require such a complicated series of steps for its operation. Therefore, the present invention can be economically and easily adapted for reclaiming containers.
2. SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a process for reclaiming plastic containers. The reclaimed plastic containers can thereafter be recycled and used in the beverage or other industries where polyethylene terephthalate or similar plastics are used.
It is another object of the present invention to provide a process for reclaiming plastic containers which is economical to operate and use.
Pursuant to the present invention, the process includes the steps of providing used beverage containers, sorting those containers according to their volume, removing the tamper resistant ring, uncapping the container if it has not already been uncapped, expanding the container through pressure, injecting heated liquid into the container, removing the label from the container, granulating the delabeled container and removing any excess liquid therefrom. The granulated container can then be recycled.
Another feature in accordance with the present invention can be the removal of the base from the container. This is particularly so, when the base and the container are composed of different plastic compositions. Further, the base can also be recycled.
Within the scope of the present invention, the containers can be sorted by volume either by hand or with an electromechanical sorter available in the industry. Further, the bottles can, if desired, be sorted by color either by hand or by any suitable device in the art.
Additionally and in accordance with the present invention, the liquid can be water or any other suitable liquid which will, loosen, dissolve and/or remove remaining residue from the container.
Further still and within the scope of the present invention, the removal of the tamper resistant seal, the uncapping of the containers can be done manually or with mechanical apparatus. Moreover, whether a container is capped or uncapped can be detected by a commercially available sensor.